The biggest Russian storage hydroelectric power station (GAES-1) is located in the Moscow region and is called Zagorskaya. Its power is 1200-1320 MW ( in the turbining and in the pump operation). Nowadays the GAES-2 is being constructed.

The GAES-1 is a unique hydroelectric project that reserves electricity returning it in the power system as the need arises.
A view from a crane that opens and closes gates of the upper pool.

This pool is artificial and made by the help of a dam.

Despite the fact that the GAES efficiency is only 75% (the production is unprofitable), its usage is economically repaid by a big difference between costs for the peak and night energy.

When the station has the surplus of electricity then hydraulic units work as pumps using cheap energy and they move water from the lower pool into the upper one at the height of 100 metres.